U.S. patent number 4,278,043 [Application Number 06/092,073] was granted by the patent office on 1981-07-14 for seat belt load indicator.
This patent grant is currently assigned to Rainsfords Metal Products Pty. Ltd.. Invention is credited to Robert B. Heath.
United States Patent |
4,278,043 |
Heath |
July 14, 1981 |
Seat belt load indicator
Abstract
A seat belt assembly provided with belt webbing, a bracket, a
buckle, and a tongue co-operable with the buckle, and one of the
bracket, buckle, or tongue is provided with a distortion area which
is under stress when the assembly is strained to the first stage of
overload.
Inventors: |
Heath; Robert B. (Lonsdale,
AU) |
Assignee: |
Rainsfords Metal Products Pty.
Ltd. (Lonsdale, AU)
|
Family
ID: |
3767851 |
Appl.
No.: |
06/092,073 |
Filed: |
November 7, 1979 |
Foreign Application Priority Data
Current U.S.
Class: |
116/28R; 116/212;
280/801.1 |
Current CPC
Class: |
A44B
11/2561 (20130101); B60R 22/18 (20130101); B60R
2022/4841 (20130101); B60R 2022/1812 (20130101) |
Current International
Class: |
A44B
11/25 (20060101); B60R 22/18 (20060101); B60R
22/00 (20060101); B60R 22/48 (20060101); B60Q
009/00 (); G01L 005/06 () |
Field of
Search: |
;116/212,56,28R
;280/801,805 ;297/468,472 ;188/1C |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Goldberg; Gerald
Assistant Examiner: Corr; Denis E.
Attorney, Agent or Firm: Holler; Norbert P.
Claims
What is claimed is:
1. A vehicle safety seat belt assembly comprising belt webbing, a
mounting bracket, a buckle, and a tongue cooperable with the
buckle,
said tongue having a first end providing walls defining a belt
webbing receiving slot, a second end for insertion into said
buckle, a distortion area of metal in the region of said first end
proximate to said second end, and a narrow neck of metal joining
said second end and said distortion area,
said distortion area having such length, breadth and depth as to
constitute a beam that bends and becomes permanently distorted when
the belt assembly is subjected to a first stage of overload and
provides an identifiable indication that the belt assembly has been
subjected to said first stage of overload, but is not destroyed so
that the belt assembly remains operable between said first stage of
overload and a second stage of overload which greatly exceeds said
first stage.
2. A vehicle safety seat belt assembly according to claim 1,
wherein said second end of said tongue has a pair of transverse
edges on opposite sides of said narrow neck and facing said
distortion area, and a cover is secured to said first end of said
tongue and has a portion normally overlying and obscuring said
edges of said second end, the extent of such obscuring of said
edges being such that upon bending of said beam under a first stage
of overload said edges become visible beyond said cover and provide
the indication that the belt assembly has been subjected to said
first stage of overload.
3. A vehicle safety seat belt assembly comprising belt webbing, a
mounting bracket, a buckle, and a tongue cooperable with said
buckle, said tongue having first and second ends the latter of
which is constructed for insertion into said buckle,
said tongue in the region of said first end having first walls
defining a belt webbing receiving slot and second walls defining a
further slot in side by side relation with said belt webbing
receiving slot, the portion of said end region of said tongue
between said slots constituting a load beam over and around which
said belt webbing extends when looped through said belt webbing
receiving slot, said load beam at each of its ends having a
respective portion of reduced width, constituting a distortion
area, to enable said belt webbing, when the assembly is subjected
to a first stage of overload, to shear the reduced width ends of
said load beam and create an identifiable indication that the belt
assembly has been subjected to said first stage of overload, and
the portion of said end region on the side of said load beam remote
from said belt webbing receiving slot and enlooped by said belt
webbing being of sufficient dimensions and strength that the belt
assembly remains operable between said first stage of overload and
a second stage of overload which greatly exceeds said first stage.
Description
This invention relates to a seat belt assembly which incorporates
an overload indicator for indicating when the belt assembly has
been subjected to a first stage of overload.
BACKGROUND OF THE INVENTION
A serious problem which is encountered with seat belt assemblies
and which has been well recognised but not yet solved is that a
seat belt assembly can be loaded with what is herein termed the
"first stage of overload", and which can for example be nine
kilonewtons although at this time no numerical load has been
identified by authorities. When so loaded, it is possible for the
webbing to become strained or the latching mechanism to be damaged
to a point where absolute security is uncertain and the seat belt
should be replaced. Such a situation can occur for example if a
vehicle is involved in a minor accident and the seat belt assembly
has "held", protecting a wearer against displacement, and it is
important that the wearer should be able to subsequently release
that belt. There is of course a second stage of overload which
occurs beyond the first stage of overload wherein the belt will
become obviously damaged and unworkable.
The main object of this invention is to provide means whereby the
seat belt assembly can be readily identified as having been
subjected to the first stage of overload even though it is still
operable.
BRIEF SUMMARY OF THE INVENTION
In this invention a seat belt assembly is provided with belt
webbing, a bracket, a buckle, and a tongue cooperable with the
buckle, and one of the bracket, buckle, or tongue is provided with
a distortion area which is under stress when the assembly is
strained to the first stage of overload.
The distortion area is of such shape and dimension that it is
permanently distorted to such an extent that the assembly is
readily identifiable as having been subjected to that first stage
of overload. However, the location and the dimensions of the
distortion area are such that the assembly remains operable between
the first stage of overload and a second stage of overload greatly
exceeding the first stage. The term "second stage of overload" is
intended herein to mean that stage of overload at which the belt
assembly becomes completely inoperable.
It will immediately be clear that there are varying places in the
assembly where the distortion area can be located, and that the
distortion can be a bending of metal, a shearing of metal, or a
deformation whereby metal is caused to flow. Conveniently the
distortion area can be located in a plate like portion of one of
the bracket, buckle or tongue.
By utilising a distortion area, the relative location of tongue and
buckle can be arranged to vary by an amount which is readily
identifiable, but the arrangement can easily be such that, after
distortion by that amount, the assembly continues to function in
the normal way.
BRIEF DESCRIPTION OF THE DRAWINGS
Several embodiments of the invention are described hereunder in
some detail with reference to and are illustrated in the
accompanying drawings in which:
FIG. 1 is a fragmentary perspective view of the anchoring device of
a buckle embodying the distortion area therein,
FIG. 2 is a similar fragmentary perspective view illustrating a
second embodiment wherein the distortion area will be subjected to
metal flow,
FIG. 3 is a plan view of a tongue having a distortion area which
will be subject to bending,
FIG. 4 is a plan view of a tongue wherein the distortion area is
subject to distortion by shearing upon overload,
FIG. 5 illustrates a fifth embodiment wherein the distortion area
is contained in the buckle and is subject to a combination of metal
flow and bending upon overload,
FIG. 6 is a section on line 6--6 of FIG. 5, and
FIG. 7 is a view corresponding to FIG. 5 which shows the condition
which exists after first stage of overload.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a mounting bracket for mounting a buckle to the
floor of a vehicle (although the invention can equally well be
applied to a mounting bracket for mounting at a high location, for
example, the centre pillar or the rear pillar of a mounting body).
The bracket 10 is provided with an aperture 11 for receiving a
securing bolt, and a distortion area 12 is formed by walls of a
slot 13, which said walls are spaced a short distance away from the
walls of aperture 11. The distortion area 12 is placed under
considerable stress when the seat belt is strained to the first
stage of overload, and the shape and dimension of the area 12 is
carefully calculated, so that it will be subject to bending,
causing one wall of slot 13 to close toward the other, but the
securing bolt will of course remain in the (now enlarged) aperture
11 so that the assembly remains operable between the first stage of
overload and the second stage of overload which greatly exceeds the
first stage wherein the assembly is damaged to the point that it
becomes inoperable for further use. By simple inspection of the
bracket 10 it will immediately become evident that the first stage
of overload has been reached, thereby being identifiable to an
inspector that the assembly should be discarded and replaced with a
new one.
FIG. 2 shows a second embodiment which is a slight variation of the
first, wherein the bracket 16 contains an aperture 17 defined by
walls to be of "key-hole" shape, that is the aperture 17 has a
relatively large portion 18 and a relatively small portion 19
extending into it. However, where the walls of the relatively small
portion 19 meet the walls of the relatively large portion 18, the
distance "d" between them is the minimum space between the slot
walls such that upon straining to the first stage of overload, the
slot walls are caused to strain apart by a metal flow (rather than
by metal bending) and the stem of the securing bolt is then located
in the relatively small portion 19 instead of the relatively large
portion 18. This again is easily and clearly identifiable by
inspection, but once again it will be seen that the location and
dimensions of the distortion area (designated 20) are such that the
assembly remains operable notwithstanding that the assembly has
been strained to the first stage of overload.
In the third embodiment of FIG. 3 a distortion area 23 is in a
tongue 24. The tongue 24 is arranged at its insertion end 25 to be
inserted into a buckle and at its belt end 26 to support a belt,
the distortion area 23 being a short beam extending between the
ends 25 and 26 which said beam will bend when subjected to the
first stage of overload. However, further bending is inhibited by
the width of the beam at the belt end 26. There is provided a cover
27 which normally obscures edges 28 of the insertion end 25 but
upon bending of the distortion area 23 due to overload the edges 28
move outwardly away from the cover 27 so that the assembly is
readily identifiable as having been subjected to the first stage of
overload. A narrow neck of metal 29 joins the insertion end 25 to
the distortion area 23.
The fourth embodiment of FIG. 4 also has distortion areas 31 in a
tongue 32, the tongue 32 also having an insertion end 33 and a belt
end 34. Walls define the belt webbing receiving slot 35 through
which the belt passes, and further walls define an adjacent slot 36
separated from the receiving slot 35 by a narrow load beam 37. The
slot 36 has walls which are parallel for most of its length, but
the ends 38 of slot 36 are widened by a reduction of the width of
the load beam 3 so that the distortion areas 31 are relatively
small in cross-section, the cross-sectional area being carefully
calculated so that upon said first stage of overload being imposed
on the seat belt assembly, the distortion areas 31 shear. Once
again it will be seen that, by virtue of the dimensions of the end
34 of the tongue enlooped by the belt webbeing when the latter is
received in the slot 35, the invention enables the belt assembly to
remain operative beyond the first stage of overload right up to the
second stage of overload, but once again it will be clear that the
distortion of the distortion areas 31 due to the first stage of
overload is readily identifiable.
The above descriptions have described the distortion area as being
in the bracket or the tongue, but it can alternatively be in the
buckle itself and FIGS. 5, 6 and 7 illustrate a fifth embodiment
wherein the buckle 41 is provided with a latching mechanism 42
controlled by a release slide 43. The buckle is provided with
covers, there being a relatively small cover 44 on the mouth and a
relatively large cover 45, which said large cover has inwardly
facing ribs 46 which engage in notches defined in walls in the edge
of the belt receiving plate 47, as seen best in FIG. 5. The belt 48
passes through a slot in the plate 47.
The plate 47 is secured to two spaced buckle plates 50 by rivets 51
and the rivets 51 pass through apertures 52 defined by walls having
a figure "8" configuration as illustrated in FIG. 5. The central
longitudinally extending slot 53 exists in the inner end of the
belt receiving plate 47, and the walls of the slot 53 and the outer
edge walls of the plate 57 cooperate with the apertures 52 to form
four distortion areas all designated 54. These distortion areas 54
are caused to bend if the assembly is subjected to the first stage
of overload as the edges of the figure "8" apertures 52 "cam" over
the shanks of the rivets 51. In so doing, the large cover 45 is
drawn rearwardly away from the mouth cover 44 by a distance
designated "D" in FIG. 7 and this enables an inspector to identify
the buckle as having been strained to the first stage of overload.
If desired a message such as "BELT STRAINED-REPLACE" can be exposed
to view through the space "D".
In the last described embodiment of FIGS. 5, 6 and 7 the slot 52
was provided with vertical walls of constant height, but as an
alternative thereto, the walls can be coined intermediate their
ends to provide inwardly facing projections which are distorted by
metal flow upon overload of the assembly in its first stage of
overload. In such a case it is not necessary to have the slot 53
since the metal on each side of the slots containing the rivets 51
is subject to much less bending.
It will be understood that the foregoing description of preferred
embodiments of the present invention is for purposes of
illustration only, and that the various structural and operational
features herein disclosed are susceptible to a number of
modifications and changes none of which entails any departure from
the spirit and scope of the present invention as defined in the
hereto appended claims.
* * * * *